Device for controlling the evaporation of volatile substances



June 13, 1961 E, sMlTH 2,988,284

DEVICE FOR CONTROLLING THE EVAPORATION OF VOLATILE SUBSTANCES Filed June12, 1958 United States Patent 2,988,284 DEVICE FOR CONTROLLING THEEVAPORATION 0F VOLATILE SUBSTANCES Dean E. Smith, 4649 N. Dover St.,Chicago, Ill. Filed June 12, 1958, Set. No. 741,549 15 Claims. (Cl.239-54) The invention relates generally to the volatilization ofmaterials and more particularly to means for controlling thevolatilization of applicable substances.

The invention has among its objects the production of a retainingstructure for volatile substances, particularly where it is desired topermit a relatively small amount of evaporation to the atmosphere over along period of time, as for example, in connection with sachets,perfumes, scenting of air, etc.

Another object of the invention is the production of articles having theabove advantages which are very simple in construction, easilymanufactured at low cost and very effective for the purposes intended.

A further object of the invention is the production of an article forcontrolling the volatiliz-ation of materials, in which the materials maybe effectively controlled over very long periods, much greater thanpresently possible, the action being subject to variations as may bedesired.

Many other objects and advantages of the construction herein shown anddescribed will be obvious to those skilled in the art from thedisclosure herein given.

-In the drawings, wherein like reference characters indicate like orcorresponding parts:

FIG. 1 is an isometric view of a container for volatile substancesconstructed in the accordance with the present invention with one cornerof the surface material broken away;

FIG. 2 is a transverse cross section of a container such as thatillustrated in FIG. 1;

FIG. 3 is an enlarged sectional view similar to FIG. 2 of a portion of ablock of material constructed in accordance with the present inventionand illustrating the apparent action involved;

FIG. 4 is a transverse sectional view similar to FIG. 2 illustrating amodified form of the invention;

FIG. 5 is a transverse section similar to FIGS. 2 and 4 of a furthermodification of the invention; and

FIG. 6 is an enlarged figure of a portion of the structure illustratedin FIG. 5.

Volatilization involves evaporation, the process of volatile moleculesmingling with the atmosphere, and in the event the evaporation takesplace in a closed vessel recondensation is also involved. The acceptedtheory with respect to evaporation in a closed vessel considers thatmolecules will leave the mother liquid and after a certain number ofcollisions with other free molecules and the sides of the vessel willfall back again into the liquid, thus involving both evaporation andrecondensation. Ultimately, in a closed vessel, the number of moleculeslost to the liquid by evaporation is deemed exactly equal to thatregained by condensation and the liquid thus becomes in equilibrium withits own vapor. If the whole liquid becomes vaporized before this stageis attained, a staple condition exists in which the vessel is occupiedsolely by free molecules of the substance, describing paths which aredisturbed only by encounters with other free molecules or the sides ofthe vessel. 7

The present invention utilizes the properties of evaporation andrecondensation to achieve effective control of the volatilization,particularly where it is desired to reduce volatilization to a degreethat will provide suitable results over a long period of time. p p

In the case of articles such as blocks impregnated with an-odor orscent, it is possible to so control the rate of evaporation, that theoriginal characteristics of the odor may be prolonged from one hundredto two hundred times the customary unrestricted rate and for even longerperiods when required. Thus it is possible to provide blocks containinga suitable scent or odor which deliver the scent to the atmosphere at arelatively precisely predetermined rate, whereby such action may beachieved from two to four years or longer, depending on the size of theblock and the specific construction thereof. Obviously these results areof particular importance and value in the manufacture of sachets and foruse in air conditioners and the like, as well as in the manufacture ofarticles where volatilization is for one reason or another desired toextend over a long period of time or in applications requiringrelatively accurately controlled volatilization.

The present invention contemplates the provision of a structure which issuitably impregnated with the volatile material to be employed, whichstructure is so designed that the action of the molecules is utilized tocontrol evaporation to the atmosphere. This is accomplished in theembodiment of the invention illustrated by providing a small chamber,passageway or tunnel in the container for the volatile substance, whichpassageway communicates with the exterior atmosphere and forms or isprovided with a restricted opening for the passage of molecules from theinterior of the device to the exterior thereof. The size of the internalpassageway as well as the opening therefrom to the exterior is soproportioned that a collision of volatile molecules takes place thereinin such a manner that there is a delay or retardation of the evaporationas well as a positive deterent on other volatile molecules which arestill in the impregnated material of the device and which otherwisewould be about to release themselves into the atmosphere.

In the case of perfumes and scents, the final odor is obtained from manyindividual components which often have different evaporation rates andwhich under normal conditions may evaporate in undesirable manners, asfor example, the most volatile being given off first, followed by thenext most volatile, etc., whereas in the ideal situation it would bedesirable that the desired mixture be given ofi substantially uniformlythroughout the discharge of the supply thereof. Tests indicate that bythe use of the present invention for perfumes or scents the apparentmolecular action is such that a continuous mixing process is apparentlyinduced among evaporating aromatic molecules of the combination so thata continuous flow of the desired complete odor the compound or mixtureis designed to convey is substantially uniformly maintained, whereby thefragrance is gently introduced in an assembled complete and continuousstate into the atmosphere without any substantial separation of itscomponent parts in the process of evaporation.

The present invention also enables further advance in connection withthe development of fragances and scents in that occasionally certaincombinations of elements can not be utilized as mixtures due toincompatability for one reason or another between the specific elements.However, with the present invention it is possible to obtain fragrancesinvolving such combinations of elements by utilizing one series ofcontainers or blocks for one element and another series of blocksassembled and intermixed therewith for the next element, etc., wherebysuch elements are never actually intermixed but only the vapors of eachintermixed as they are discharged from their respective containers.

Referring to the drawings and more particularly to FIGS. 1, 2 and 3, thereference numeral 1 indicates generally a container structure forvolatile substances constructed in the form of a block 2 of suitablematerial. having a porous character whereby it is capable of beingaasaasa impregnated with volatile material or substance. The block 2 maybe of any suitable material, as for example wood, cellulose, fiber,pulp, filament, silicate, gum, plastic or the like, capable of beingimpregnated by suitable means with a volatile substance, as for example,by submerging it in a solution of the volatile substance either beforeor after the block is formed.

For the purposes of explanation, the invention will be described indetail in connection with blocks of a size suitable for use in sachetsof the like, in which case a very effective size of block has been foundto be in the form of approximately a five thirty-seconds of an inchcube. However, depending upon the nature of the use, the blocks normallywill run from approximately one-sixteenth of an inch square tothree-quarters of an inch square, and for air conditioning and the likemay involve larger blocks as hereinafter described. Following theformation of the impregnated block, the contents is then substantiallyhermetically sealed by an air tight coating of suitable material such asshellac, lacquer, varnish, gum, wax, casein, resins, plastic or othersuitable bland, reasonably hard coating, or-combination thereof. It willbe appreciated that in such case the impregnating material is containedin a substantially air tight retainer generally corresponding to aclosed glass bottle, etc. The coating 3 may be applied in any suitablemanner, as for example, dipping, spraying or the like.

When the coating has suitably hardened or set to permit furtherprocessing, the coated block is then formed with .a passageway or tunnel4 therein, which may be suitably accomplished by boring or-drilling, orunder suitable conditions by a punching operation or may even beconstructed by a molding or forming operation. Normally thesize of thepassageways or tunnels 4 will range from one two-hundredths of an inchto three sixteenths of an inch in diameter. In the case of a fivethirty-second inch cube with approximately one sixty-fourth inchdiameter bore therethrough, a sachet of approximately onehalf ounce inweight would contain from forty to eighty blocks depending onconstruction and design of the sachet.

If the basic material, as for example raw wood, is utilized for theblocks and thus initially contains deleterious matter, such materialmust be suitably conditioned to remove such matter, which in the case ofwood may be readily accomplished by boiling from four to ten hours orlonger in ten or more changes of water, by the use of live steam, or byextraction in an extracter using hot ether. After conditioning, theblocks should be completely dried by suitable heat such as in an oven,until all traces of moisture are removed. In the case of wood, wellseasoned hard maple, or any mature well seasoned firm wood whosestructure remains intact and will satisfactorily hold the desiredimpregnating materials is suitable. Normally the small sized wood andcellulose blocks can be impregnated without any increase in atmosphericpressure, but in the use of large sized wood blocks of considerabledensity, a pressure of three or more atmospheres may be required undercontrolled temperatures to suitably drive the impregnating material inthe block.

The ratio between the size of the block and tunnel would appear to be inalmost direct proportion to the length of time required for completeevaporation. Consequently it would appear to be desirable that theblocks and tunnels remain as small as possible to accomplishsatisfactory results where a long period of time is desired fordissipation. For example, taking an odor of a determined intensity thatwill last two years with a given size of blocks and tunnels can be madeto last about four years by using double the quantity of the same sizedblocks but using only half the size of tunnel utilized for the two yearperiod. Thus various combinations of block material and size of blocksand tunnels can be used to achieve the desired results.

The blocks may be kept loose in a container, or may beLsecured in acontainer by any suitable means, as for example, setting in indentationsor grooves and the like, or by means of suitable strands passing throughtunnels to hold the blocks in place.

It will be apparent from the above description that it becomes possibleto utilize normally incompatible substances in arriving at a desiredodor which heretofore could not be suitably accomplished, theincompatible substances being contained in separate blocks wherein thevapors of each substance may be mingled and combined without bringingthe incompatible substances into physical or chemical contact with oneanother or other ingredients. Thus a whole field for the creation of newodors, heretofore impractical, can be obtained. Likewise the creation ofnew odors may be obtained in a manner analogous to the three colorsystem employed in lithography, wherein three color plates aresuperimposed to create a complete range of colors.

Various examples could be given of incompatibility rendering certaincombinations impractical. For example, each of the artificialnitro-musks, ambrette, ketone and xylol has a highly desirable scent,nuance or side note, but their uses are restricted in many combinationsbecause these substances in some compositions tend'to create a chainreaction with other ingredients in the compound, which in course of timedeteriorates or destroys the originally desired scent. By confiningartificial musk substances or afiiliates dissolved in suitable materialsuch as benzyl, benzoate, diethyl, phthalate or other solvents inseparate impragenated blocks in an assembled combination, the fine scentof artificial musks or afliliates can mingle with notes of the remainderof the combination to create a highly desired scent without bringing theartificial musks or aifiliates into physical or chemical contact withthe other ingredients of the combination.

Similarly, various sizes of blocks of various materials and varioussizes of tunnels can be used in the same sachet to obtain a timed andbalanced result. For example, fugitive odors such as flower absolutescan be impregnated into separate blocks to lengthen their period ofevaporation so that their notes will last as long as the heavier notesinvolved throughout the entire life of the combination.

As illustrated in FIG. 4, in some cases it'may be .desirable to drillthe tunnel 4 only partially through the block rather than completelythrough as illustrated in FIG. 2. This might be true, for example, inthe case of a delicate flower absolute, duly fixed with a bland"fixative if required, which could be contained in blocks of suitableproportionate size with small tunnels measuring one one-hundredth of aninch or smaller in diameter and extending only one-third to one-half thedistance through each block.

The invention is also applicable to correction of air in air conditionersystems and the like, where it is usually intended to lend a slightnuance to the air after it has passed through a clarifying or washingprocess. Blocks for this purpose may be considerably larger than thoseheretofore described, normally measuring up to approximatelythree-quarters of an inch in diameter and up to four inches in length,in which case the block would be very similar to that illustrated inFIG. ,2, with the exception that it is of greater length in thedirection of the axis of the tunnel 4. In most cases the blocks will beimpregnated with a special neutral behavior fine type scent of agreeableand delicate pattern having gentle notes carried in extreme dilution toefiectively correct and neutralize reconditioned air so that the scentwill remain discreet and almost imperceptible. Consequently blocks forthis purpose may be constructed of suitable size, as for example, asabove set forth, with the tunnels extending down the center and ofapproximately three-sixteenths of an inch in diameter. In this case theblock, following impregnation, may be provided with suitable plugs ofwood, plastic or other suitable material at each end of the tunnel,thereby effectively restricting acsaasa.

the open end of the latter. The block then may be coated and each plugformed with a small bore having a diameter of one-sixteenth of an inchto about one-sixty fourth of an inch or smaller, depending on thequantity of circulating air the blocks are called upon to serve.

FIGS. and 6 illustrate bores formed in this manner, the block 2' having,in this case, a plurality of bores 4' which are provided at each endwith a suitable plug 5' over which the exterior coating 3 extends. Eachof the plugs is provided with a small bore 6 extending therethroughoperatively connecting the interior of the tunnel 4, with the exteriorof the block.

Where the invention is employed in air conditioning systems and the likewherein the larger or elongated type of block is employed, the blockswill usually be suitably supported so that the air flow is transversewith respect to the axis of the tunnels, and thus not flowing throughthe tunnels.

FIG. 6 also illustrates a construction which may be desirable in certaininstances wherein the block 2 has a transverse dimension which is moreor less a multiple of the general configuration illustrated in FIGS. .1,2 and 3 and a plurality of tunnels which are suitably spaced in theblock. The block 2. illustrated in FIG. 5 vertically is substantiallythe equivalent of approximately four blocks assembled with similar longsides abutting one another and each block provided with its respectivetunnel. i

As illustrated in FIG. 6, the molecular action of a construction such asillustrated in FIG. 5 is believed to be similar to that illustrated inFIG. 3.

The effectiveness of the tunnel structure and the manner hereindescribed may be readily demonstrated by taking two blocks which areidentical as to size, shape, impregnation and coating, providing oneblock with a tunnel in accordance with the present invention and merelyremoving a portion of the coating equivalent in area to the crosssectional area of the tunnel at its mouth. The omission of the tunnelwould result in a more or less uninterrupted evaporation of the volatilesubstance to the atmosphere and such substance would exhaust its odor ina relatively short period of one to three months as compared with two ormore years where the present invention is employed. Also in the process,the evaporation would be fractional and spotty, i.e. the compound in thecourse of evaporating would resolve itself into its various components,with the result that the lighter and more volatile portions wouldexhaust themselves first, leaving the heavier components to evaporatetoward the end of the life of the substance. Such action often bringsout an odor of raw materials that may become unpleasant and highlyundesirable.

It might also be mentioned that in previous devices, as for example oldstyled sachets, outside undesirable odors may be absorbed, impregnatingsurfaces tending to draw seepage from the outside atmosphere. As suchunwanted outside odor mingles with the impregnated material to create ahybrid product, the result is an odor. that can become rancid, tiresome,dead or extremely obnoxious. With the present invention the small sizeof the tunnel openings in the blocks in relation to molecular forcedriving scent out of the blocks would appear to substantially completelyprevent any outside unwanted odors from coming in. This is of particularimportance because sachets are often required to overcome other odors ina place of storage.

It will be appreciated from the above disclosure that the presentinvention has among its functions the control, not only of the rate andduration of evaporation, but also control of the behavior ofevaporation. Perfumes yield their finest fragrance in difiused andsubtle form, and with the device herein described this is achieved byrestraint which enables the finest top notes to manifest themselvesthroughout the entire period of evaporation of the compound withoutbecoming subdued or overwhelmed by heavier components which may berequired in the per-fume compound to compose a better balanced odor anda finished scent.

While I have illustrated the blocks as being of rectangular crosssection, it is believed apparent that various configurations may beemployed, as for example, spheres, cylinders, octagons, bars of variousshapes, etc. While I have described the invention in connection withfragrant scents or odors such as perfumes and the like, it is believedapparent that the invention may have applicability in other unrelatedfields involving the use of volatile substances wherein it is desiredthat the latter be volatized over a prolonged period at a controlledrate in accordance with the invention.

Having thus described my invention, it will be obvious to those skilledin the art that various immaterial modifications may be made in the samewithout departing from the spirit of my invention, hence I do not wis-hto be understood as limiting myself to the exact form, construction,arrangement and combination of parts herein shown and described, or usesmentioned.

What I claim as new and desire to secure by Letters Patent is:

1. A device for controlling volatilization of a volatile aromaticsubstance over a relative long period of time, comprising a block ofmaterial having a porous relatively non-volatile structure containing asupply of a volatile aromatic substance therein, the volume of saidblock ranging from approximately M1096 cubic inch to approximately 2%cubic inches and the dimensions of said block ranging from approximatelyM x 4; x V to %1 x x 4", said block having a substantially imperviouscoating thereon of high impermeability to the volatile aromaticsubstance, said block having a mixing passageway for the volatilearomatic substance therein extending to at least one face of the block,said mixing passageway having an effective diameter ranging from 54 to/56", said substantially impervious coating having an opening thereinoperatively connecting said mixing passageway with the exterior throughwhich molecules of the volatile aromatic substance may flow, saidopening ranging in effective diameter from hoo to operative to produce amolecular action within the mixing passageway that tends to approach anequilibrium in evaporation and recondensation, resulting in acomparatively small relatively uniform discharge of molecules from saidopening for the mixing passageways over a relatively long period oftime, and said substantially impervious coating of the block directingthe volatile aromatic substance towards said mixing passageway.

2. A device as defined in claim 1, wherein said device comprises aplurality of said blocks, the latter being impregnated with the volatilearomatic substance including constituents of a desired scent, saidsubstantially impervious coating comprising a material which. isrelatively inert with respect to such constituents and forms asubstantially air'tight coating on each of said blocks.

3. A device as defined in claim 2 wherein different constituents arecontained in respective blocks, the size of said blocks and the size ofsaid passages being selected to provide desired molecular discharges inthe respective blocks operative to achieve a desired combined eifectover a-relatively long period of time.

4. A device as defined in claim 1, wherein said opening in thesubstantially impervious coating is smaller in area than thecross-sectional area of said mixing passageway.

5. A device as defined in claim 1, wherein said mixing passageway has aplug therein at the adjacent face of the block on which said mixingpassageway opens, said plug having a bore therein operatively connectingthe mixing passageway with the exterior, the cross-sectional area ofsaid bore being less than that of the mixing passageway.

6. A device as defined in claim 1, wherein said mixing passagewayextends through the block and said substantially impervious coating hasan opening therein for each end of the mixing passageway.

7. A device as defined in claiml, wherein said block has a. plurality ofmixing passageways therein, extending in spaced parallel relation withrespect to one another.

8. A device as defined in claim 7, wherein said mixing passageways areprovided with plugs at each end thereof, each plug having a relativelysmall bore therein and operatively connecting its respective mixingpassageway with the exterior.

9. A device as defined in claim 1, wherein said block is of wood andsaid substantially impervious coating including one or more materialsselected from a group consisting of shellac, lacquer, varnish, gum, wax,casein, resins, plastic, and other suitable bland, reasonably hardcoating.

10. A device as defined in claim 2, wherein the size of the openings incertain blocks are larger than that of openings in other of such blocks.

11. A device as defined in claim 2, wherein certain of the blocks arelarger than others and the larger blocks are provided with largeropenings than those of the smaller blocks.

12. A device as defined. in claim 1, wherein said substantiallyimpervious coating is a suitable bland, reasonably hard coating.

13. A device as defined in claim 1, wherein said substantiallyimpervious coating includes a suitable bland, reasonably hard coating incombination with an additional material.

15. A device as defined in claim 1, wherein said block of material is ofa material selected from a group consisting of wood, ce1lu1ose,,fiber,pulp, filament, silicate, gum,

and plastic capable of being impregnated with a volatile material andsaid substantially impervious coating including one or more materialsselected from a group consisting of shellac, lacquer, varnish, gum, wax,casein, resins, plastic, and other suitable bland, reasonably hardcoating.

References Cited in the. file of this patent UNITED STATES PATENTS1,358,928 Boehm Nov. 16, 1920 1,454,236 Gunnell May 8, 1923' 1,479,704Duddleson Jan. 1, 1924 1,889,075 Mills Nov. 29, 1932 2,547,687 BrodyApr. 3, 1951 Holt Jan. 31, 1956

